No evidence that DNA sequence used in Pfizer shot leads to cancer and other health issues
FILE - Pharmacist Sima Manifar prepares a children’s dose of the Pfizer COVID-19 vaccine during a vaccination clinic at City of Lawrence’s “The Center,” which serves seniors, families and the community, Wednesday, Dec. 29, 2021, in Lawrence, Mass. The Associated Press on Monday, Nov. 20, 2023 reported on social media posts falsely claiming that the company’s shot contains a DNA sequence called Simian Virus 40 that can cause health problems, including cancer. (AP Photo/Charles Krupa)
CLAIM: Pfizer’s COVID-19 vaccine contains a DNA sequence called Simian Virus 40 that can cause health problems, including cancer.
AP’S ASSESSMENT: False. No evidence has been found to suggest DNA fragments used in the development of the coronavirus vaccine -- such as a portion of SV40’s DNA sequence -- are causing health problems in people who have received the COVID-19 vaccine.
THE FACTS: A congressional hearing has revived baseless claims that coronavirus vaccines contain dangerous levels of monkey virus DNA.
Social media users are sharing a post from The Epoch Times website that says Congress was warned at a recent hearing about “DNA fragments” detected in the inoculation made by Pfizer and BioNTech.
The post explains that Dr. Robert Malone, who played a role in developing the messenger RNA, or mRNA, technology used in the vaccine, testified that the shot includes a DNA sequence called Simian Virus 40, or SV40.
“The sequence leaves behind residual DNA that could cause problems,” reads the Instagram post, which references an Epoch Times story that cites cancer, genetic abnormalities in developing fetuses and other alleged health risks. But the Nov. 13 hearing at the U.S. Capitol, which was held by Rep. Marjorie Taylor Greene and other vaccine critics in the House of Representatives, repeated long debunked falsehoods about the contents of the shot and their purported health risks.
Government regulatory agencies and vaccine experts told The Associated Press that the Simian Virus itself isn’t present in the vaccine, and there’s no evidence anything contained in the vaccine could alter a person’s DNA or lead to cancer and other illnesses.
The European Medicines Agency, which regulates vaccines in European Union nations, explained that “non-functional” fragments of SV40’s DNA sequence are used as “starting material” in producing the vaccine.
But those materials are broken down and removed in the manufacturing process. Trace amounts might still remain at “very low levels” in the final product, the agency and others acknowledged, but they are well within established safety guidelines.
“EMA has seen no evidence of an association between mRNA vaccines and adverse events that could be linked to the presence of DNA material, nor are we aware of any scientific evidence showing that the very small amounts of residual DNA that may be present in vaccine batches could integrate into the DNA of vaccinated individuals,” the Amsterdam-based agency wrote in an emailed statement.
The Food and Drug Administration, which regulates vaccines in the U.S., echoed the sentiment, saying no safety concerns about residual DNA in COVID vaccines have been identified, despite more than one billion shots being administered.
“The FDA stands behind its findings of quality, safety, and efficacy for the mRNA vaccines,” the agency wrote, deferring further questions to Pfizer and other vaccine makers.
Pfizer, in an emailed statement, stressed that the use of the SV40 sequence is common practice in developing vaccines, including the influenza and hepatitis shots that have been administered globally for decades.
“There is no evidence to support claims that the Pfizer-BioNTech COVID-19 vaccine contains plasmid DNA that could potentially impact a person’s DNA or be a theoretical cancer risk,” the company wrote, referring to DNA materials used to trigger an immune response during vaccine development.
Spokespersons for The Epoch Times didn’t respond to messages seeking comment on Monday.
But Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, argued that the amount of DNA material present in the COVID vaccine pales in comparison to the level for foreign DNA ingested by people every day simply by eating plants and animals.
Moreover, he said, it would take much more than a fragment of DNA to alter a person’s genetic code, as the posts claim.
“One, it’s very hard for a DNA fragment to enter a cell, specifically its nucleus, where the DNA resides,” Offit explained in a phone interview Monday. “Your cytoplasm -- the white egg part of your cell -- doesn’t like DNA and has a variety of mechanisms to rid itself of DNA.”
“Two, for that fragment of DNA to be integrated into your DNA, you also have to have enzymes that disrupt the DNA and allow you to insert that fragment,” he continued. “That’s what gene therapy is all about, and that’s what makes gene therapy so hard to do.”
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This is part of AP’s effort to address widely shared misinformation, including work with outside companies and organizations to add factual context to misleading content that is circulating online. Learn more about fact-checking at AP.
